<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>div&span</title>
</head>
<body>
    <div style="background-color: green;">
        123
        <br>
        456
    </div>
    <div style="background-color: pink;color: chartreuse; height: 300px;">
        div有自动换行功能
    </div>
    
    <span style="color: white;background-color: palevioletred;">span</span>
    <span>span没有自动换行</span>

  <!--  可以理解为div是一个独占一行的大盒子
        span是一个小盒子 -->
</body>
</html>